java - not able to retrieve string from parse database with query -

i'm trying retrieve information parse object strings store them in keep equaling null.

here how saved object

        // current user         parseobject studentclasses = new parseobject("studentclasses");          // register periods database         studentclasses.put("student_id", parseuser.getcurrentuser());         studentclasses.put("first_period", classselected_period[period1]);         studentclasses.put("second_period", classselected_period[period2]);         studentclasses.put("third_period", classselected_period[period3]);         studentclasses.put("fourth_period", classselected_period[period4]);         studentclasses.put("fifth_period", classselected_period[period5]);         studentclasses.put("sixth_period", classselected_period[period6]);         studentclasses.put("seventh_period", classselected_period[period7]);          // save information database         studentclasses.saveinbackground(); 

it saves fine database. student_id pointer user , rest of columns strings.

i want retrieve strings , put them in array when query parse them doesn't work

here query

        // check if user not cached         parseuser currentuser = parseuser.getcurrentuser();         if (currentuser == null)         {             // prompt user register screen             // create intent start activity             intent intent = new intent(mainactivity.this, registeractivity.class);             intent.addflags(intent.flag_activity_clear_top);              // start new activity             startactivity(intent);              // stop current activity             finish();         }          // query database user's classes         parsequery<parseobject> query = parsequery.getquery("studentclasses");         query.whereequalto("student_id", parseuser.getcurrentuser());          query.getfirstinbackground(new getcallback<parseobject>()         {             @override             public void done (parseobject parseobject, parseexception e)             {                 if (e == null)                 {                     // retrieved object                     userclasses[period1] = parseobject.getstring("first_period");                     userclasses[period2] = parseobject.getstring("second_period");                     userclasses[period3] = parseobject.getstring("third_period");                     userclasses[period4] = parseobject.getstring("fourth_period");                     userclasses[period5] = parseobject.getstring("fifth_period");                     userclasses[period6] = parseobject.getstring("sixth_period");                     userclasses[period7] = parseobject.getstring("seventh_period");                 }                 else                 {                     // failed lookup. here                     toast.maketext(getapplicationcontext(),"exception thrown" ,toast.length_short).show();                 }             }         }); 

i looked @ parse docs , looks should work doesn't save strings

any or comments appreciated thanks!

edit: showed more of code query part show there current user

here assuming that, there data stored in parse database.. , works fine.. retrieve try following..

 parsequery<parseobject> query = parsequery.getquery("studentclasses");     query.whereequalto("student_id", parseuser.getcurrentuser());      query.findinbackground(new findcallback<parseobject>()     {         @override         public void done (list<parseobject> list, parseexception e)         {             if (e == null)             {                for(int i=0; < list.size(); i++) {                 userclasses[period1] = list.get(i).getstring("first_period");                 userclasses[period2] = list.get(i).getstring("second_period");                 userclasses[period3] = list.get(i).getstring("third_period");                 userclasses[period4] = list.get(i).getstring("fourth_period");                 userclasses[period5] = list.get(i).getstring("fifth_period");                 userclasses[period6] = list.get(i).getstring("sixth_period");                 userclasses[period7] = list.get(i).getstring("seventh_period");                }             }             else             {               toast.maketext(getapplicationcontext(),"exception thrown" ,toast.length_short).show();             }         }     }); 

hope helps!